Steep slopes, embankments, and sub-grades of earth often require stabilization to prevent soil movement. Often, stabilization can be accomplished by using high quality, select soils in the slopes or embankmnents. However, it is often desirable to reuse the soils originally found at the construction site. In such cases, it is often necessary to construct additional structures for effective stabilization of the soil.
Although some soil stabilization applications are effectively achieved by using underlayments and layers of sheet materials, or anchor sheets, which are covered with backfill materials, other applications require the construction of retaining walls. Moreover, some applications require the construction of retaining walls that incorporate anchor sheets for maintaining the retaining wall and soil in their desired positions. Existing retaining walls are typically constructed of a plurality of uniformly shaped, molded blocks which may either be connected together or simply stacked atop each other. For example, some known blocks have bores which receive pins or dowels to connect the molded blocks in vertically adjacent tiers. Still other types of existing molded blocks have opposing top and bottom surfaces which are often configured for interlocking engagement.
As noted, existing retaining walls may also include one or more laterally extending anchor sheets that maintain both the retaining wall and the retained soils in the desired positions. Typically, a portion of each anchor sheet is attached to the retaining wall by the use of connectors, such as clips, pins, etc. disposed in matching holes, etc., or the retained portion may be merely secured between adjacent tiers of molded blocks by the weight of the blocks.
Retaining walls may also be constructed of blocks of naturally occurring stone materials, such as granite, flagstone, fieldstone, etc. Because the blocks of naturally occurring stone material are quarried from the earth rather than being formed in a mold, they typically vary in shape from one block to the next. There are a number of drawbacks of existing retaining walls constructed of natural stone materials. For example, because the blocks are non-molded and non-uniform, they are not as readily stackable as their modular counterparts. As a result, whereas the retaining wall constructed of molded blocks may have a fairly uniform width from the base to the top of the wall, a retaining wall constructed of non-molded, natural stone material typically requires a width at the base of the wall which can be up to as much as one-half the overall height of the wall. As such, typical retaining walls constructed of non-molded blocks require large amounts of materials, and they are rather expensive to construct.
Therefore, there is a need for improved retaining wall structures constructed of naturally occurring, non-molded blocks which address these and other shortcomings of the prior art.